Fix blur background in the same class level and add blur background in default tile

less/background.less

@@ -5,10 +5,10 @@
 @background-color-opacity: @global-opacity;
 
 .hook-background-misc() {
-  .set-blur-background();
+  .set-blur-background(@background-default-background, 80%);
 
   .uk-background-default {
-    .set-blur-background(@background-default-background);
+    .set-blur-background(@background-default-background , 80%);
   }
 
   .uk-background-primary {

less/mixin.less

@@ -1,13 +1,20 @@
 .set-blur-background(@color: @base-body-background, @opacity: 80%) {
-  .uk-blur-background {
-    background: fade(@color, @opacity + 15%);
+  &.uk-blur-background, .uk-blur-background {
+    background: fade(@color, 99%);
   }
 
   @supports ((-webkit-backdrop-filter: none) or (backdrop-filter: none)) {
-    .uk-blur-background {
+    &.uk-blur-background, .uk-blur-background {
       -webkit-backdrop-filter: saturate(180%) blur(20px);
       backdrop-filter: saturate(180%) blur(20px);
       background: fade(@color, @opacity);
     }
   }
+
+  /* for firefox */
+  @-moz-document url-prefix() {
+    &.uk-blur-background, .uk-blur-background {
+      background: fade(@color, 99%);
+    }
+  }
 }

less/offcanvas.less

@@ -27,7 +27,7 @@
 @offcanvas-overlay-background: @global-overlay-background;
 
 .hook-offcanvas-bar() {
-  .set-blur-background(@offcanvas-bar-background);
+  .set-blur-background(@offcanvas-bar-background, 80%);
 }
 
 .hook-offcanvas-misc() {

less/tile.less

@@ -1 +1,5 @@
 @tile-default-background: @global-inverse-color;
+
+.hook-tile-default() {
+  .set-blur-background(@tile-default-background, 50%) !important;
+}